In the typical course of electronic communication, increasing amounts of data are stored, manipulated and deleted. As the demands for storage space increase, storage density becomes increasingly important. Shingled magnetic recording (SMR) techniques have been developed as one way to increase storage density at a device level, but devices using SMR techniques have certain operational characteristics that may be taken into account when they are deployed in data storage systems. For example, it may be impractical to write data to SMR devices in a non-sequential fashion, similarly to many tape-based storage devices. On such devices, the deletion of data may most conveniently occur by updating a record reflecting the data after the data has been written, and not by physical erasing the data. Thus, as a level of deletion on a sequentially-written device increases, available space for additional data storage may not increase proportionally. Additionally, especially in the case that a deleted portion of data is replaced with another piece of data that is sequentially written, data fragmentation tends to increase.